Solid propellant and process using vinyl decaborane compounds



United States Patent fiice WW3 Patented July 21, 1964 bis(acetonitrilo)decaborane in benzene at refiux for 24 3,141,803 hours. SOLID PROPELLANT AND PROCESS UsING The solid inorganic oxidizers useful in forming the solid VINYL DECABORANE COMPOUNDS ro ellant rains of this inv ntion includ i Joseph Green, Dover, and George J. Donovan, Boonton, p g e 1 e ammon um N.J., assignors to Thiokol Chemical Corporation, Bris- 5 crate and the alkah. metal perch Crates l as tel, Pa, a corporation of D l sodium perchlorate, potassium perchlorate, and lithlum No Drawing. Filed May 5, 1961, Ser. No. 108,193 Perchlorate, ammonium nitrate and the alkali metal n1- 4 Claims. (Cl. 149-19) trates such as sodium nitrate, potassium nitrate and lith- This invention relates to liquid compositions curable The preparation and curing of the liquid compositions to form tough elasto ners sef l as the f e -bind r c mof this invention is illustrated by the following examples. ponent of a composit lid propellant grain- Th n- In all of the examples, the liquid urethane polymer emvention also relates to solid propellant grains produced .ployed wa Adiprene L, whi h i a fully saturated from the liquid compositions. In particular the invendiisocyanate reaction product with a polyetherglycol contion relates to solid propellant grains having a high burnl5 taining 4,0 to 4.3% by weight of isocyanate groups. ing rate produced by use of borane additives.

The liquid compositions generally include to 80 EXAMPLE 1 parts by weight of a liquid polymer, 1 to 50 parts by Into a container jacketed for heating oil circulation and weight of a curing agent and 80 to 20 parts by weight equipped with mixing means and means for evacuation of a liquid organoboron compound of the class 20 were placed 100 parts by weight of Adiprene L and 100 parts by weight of C-isopropenylvinylenedecaborane (IPVD) of the formula IU lO-n CH3 RI/n wherein R and R are each hydrogen, alkyl radicals or CH2 alkenyl radicals, R" is a lower alkyl radical, and n varies from 0 to 4. The container was sealed, evacuated and mixing was start- Composite solid propellant grains are produced by ed and continued until a homogeneous mix which had admixing from 5 to 40 parts by weight of the above been completely degassed was obtained. The mixer was liquid compositions with from about 25 to 60 parts then stopped and the container brought to ambient presby weight of a solid inorganic oxidizer and heating the sure. The container was opened and 11 parts by weight resulting admixture at a temperature within the range from of methylene bis-orthochloroaniline were added. The conabout 25 to 120 C. for from about 4 hours to 7 days. tainer was then again sealed, evacuated and the contents Examples of liquid polymers useful in preparing the m1xed until a homogeneous mix which had been comcompositrons of this invention include diisocyanate termipletely degassed was obtained The mixer was stopped, nated polyesters, polyesteramides, polyetherglycols, and the container was brought to ambient pressure, opened, hydrocarbon polymers terminated with carboxy groups and the contents cast into a mold. The mold was then such as carboxylated polybutadiene. Curing agents for placed in an oven at 100 C. to cure for 330 minutes. the polyurethanes include polyols, polyamines, titanate At the end of this time, the mold was removed from esters and amines and epoxy resins for the carboxy polythe oven and cooled to room temperature. Examinamers tion of the sample showed that a tough elastic cure was The liquid organoboron compounds useful in preparing obtained. Pertinent data for additional examples are the compositions of this invention can be prepared by shown in the following Table I.

Table I Durom- Time Temp. Adiprene IPVD TBS eter (Min) 0.) Comments Shore A 100 330 100 Excellent cure-good strength. 100 100 330 100 Undercured. 100 315 100 Good elastic cure. 100 100 420 100 Excellent curegood strength. 100 100 420 100 Good tight cure. 100 100 420 100 Undercured. 100 100 420 100 N o cureviscous liquid. 100 100 420 100 D0. 100 100 420 Viscous liquid. 100 420 80 Semi-solid. 100 100 420 80 Viscous liquid. 100 100 420 80 D0. 100 100 20 hrs. 100 Excellent elastic cure. 100 100 20 hrs 100 D0. 1 TBS-tributyl sebacate. the method described In application Serial No. 59,460, EXAMPLE l5 filed September 29, 1960, of lack Bobinski and Marvin In I d M. Fein and Nathan Mayes. For example, C-isopro- 5 w g fi a sol i i propellant gram penylvinylene-decaborane of the formula as prepare e prope an was .comPounded In a vacuum sealed Baker-Perkins type mixer acketed 0 3 for heating oil circulation. To the mixing basket were CH2C C=C H added 100 parts by weight of Adiprene L and 100 parts l 70 by weight of C-isopropenylvinylenedecaborane. The

chamber was evacuated and the temperature was brought can be prepared by heating isopropenyl acetylene with up to 40 C. Mixing was then started and continued until 3 V :ompletely degassed homogeneous mix was obtained. a mix was cooled, the mixer stopped and the chamber )ught to ambient pressure and opened. To the mixbasket were then added 637 parts by weight of am- )nium perchlorate together with 032 part by weight 5 copper chromite. The chamber was again sealed d evacuated, the temperature raised to 40 C., and mixstarted and continued unt'l a degassed homogeneous .x was obtained. Again the mix was cooled, the mixer pped and the chamber brought to ambient pressure. the mixing basket were then added 11.9 parts by eight of methylene bis-orthochloroaniline and the heatg and mixing procedure was repeated. The cooled propellant mix was castable at room temerature and was removed and cast in a mold. The \Old was placed in an oven at 100 C. to cure for 660 tinutes at the end of which time it was removed from 1e oven and cooled. The resulting composite solid proellant grain was a strong rubbery mass with no porosity. 'ertinent data for additional examples are Table II.

Table 11 Exp 15 16 17 xdiprene L--. 100 100 100 .PVD 100 100 100 yioca 11.9 11 5 Jopper Chromite 0. 32 0. 5 0. 5 Ammonium Perchlorate 637 634 616 During Cycle: Time (Mi 660 660 660 Temp. C. 100 100 100 Processing Cast Cast Cast.

For best results, the polyurethane curing agent should be present in an amount of about 8% to 12% by weight of the liquid urethane polymer. Also the use of about 0.5% copper chromite, based on the weight of the solid inorganic oxidizer, was found to aid materially in the castability of the propellant mixes. The liquid organoboron component of the liquid vention serves both as a plasticizer in and to provide a high energy content to the cured composite solid propellant grain.

The composite solid propellant grains of this invention are suitable for use in rocket other jet propelled devices. They burn with high flame speeds, have high heats of combustion and are of the high specific impulse type. They burn uniformly without disintegration when ignited by conventional means,

shown in 20 compositions of this in- 40 power plants and such as a protechnic type igniter, and are mechanically strong enough to withstand ordinary handling.

We claim:

l. A liquid composition curable to form a tough elastomer useful as the fuel-binder component of a composite solid propellant, said liquid composition consisting essentially of 20 to '80 parts by weight of a liquid polymer selected from the class consisting of diisocyanate terminated polyesters, diisocyanate terminated polyesteramides, diisocyanate terminated polyetherglycols and carboxy group terminated hydrocarbons, 1 to parts by weight of a curing agent, and to 20 parts by weight of an organoboron compound of the class RC==GR' 1516 6-11 Blfn wherein R and R are each selected from the class consisting of hydrogen, alkyl radicals and alkenyl radicals,

is a lower alkyl radical, and It varies from 0 to 4.

2. The liquid composition of claim 1 wherein the liquid polymer is a fully saturated diisocyanate terminated polyetherglycol, the curing agent is methylene bis-orthochloroaniline, and the organoboron compound is C-isopropenylvinylenedecaborane of the formula 3. A method for preparing a composite solid propellant grain which comprises heating at a temperature within the range from about 25 to 120 C. for from about 4 hours to 7 days an admixture consisting essentially of from about 60 to parts by weight of a solid inorganic oxidizer and from about 5 to 40 parts by weight of a composition of claim 1.

4. A method for preparing a composite solid propellant grain which comprises heating at a temperature within the range from about 25 to C. for from about 4 hours to 7 days an admixture consisting essentially of from about 60 to 95 parts by weight of ammonium perchlorate and from about 5 to 40 parts by weight of a composition of claim 2.

References Cited in the file of this patent UNITED STATES PATENTS 

1. A LIQUID COMPOSITION CURABLE TO FORM A TOUGH ELASTOMER USEFUL AS THE FUEL-BINDER COMPONENT OF A COMPOSITE SOLID PROPELLANT, SAID LIQUID COMPOSITION CONSISTING ESSENTIALLY OF 20 TO 80 PARTS BY WEIGHT OF A LIQUID POLYMER SELECTED FROM THE CLASS CONSISTING OF DIISOCYANATE TERMINATED POLYESTERS, DIISOCYANATE TERMINATED POLYESTERAMIDES, DIISOCYANATE TERMINATED POLYETHERGLYCOLS AND CARBOXY GROUP TERMINATED HYDROCARBONS, 1 TO 50 PARTS BY WEIGHT OF A CURING AGENT, AND 80 TO 20 PARTS BY WEIGHT OF AN ORGANOBORON COMPOUND OF THE CLASS
 3. A METHOD FOR PREPARING A COMPOSITE SOLID PROPELLANT GRAIN WHICH COMPRISES HEATING AT A TEMPERATURE WITHIN THE RANGE FROM ABOUT 25* TO 120*C. FOR FROM ABOUT 4 HOURS TO 7 DAYS AN ADMIXTURE CONSISTING ESSENTIALLY OF FROM ABOUT 60 TO 95 PARTS BY WEIGHT OF A SOLID INORGANIC OXIDIZER AND FROM ABOUT 5 TO 40 PARTS BY WEIGHT OF A COMPOSITION OF CLAIM
 1. 